alcohol % question?

[michaelob]

I just bottled a irish stout recipe kit from north west and I still cant figure out the % . OG was 1.040 and FG is 1.020. im hoping to be around 4%. its only my 3rd brew and im still unsure.

 

[Yuri_Rage]

(OG - FG) * 131

So, if your measurements were correct, it is 2.6% ABV. However, both numbers look incorrect. What was the recipe? How long did it ferment? At what temperature did you take your readings? 1.020 is WAY too high of an FG for a beer that started at 1.040. Let's hope that your measurements were wrong, or you're in for bottle bombs.

 

[michaelob]

my recipe was a extract kit from northwest. it fermented for 2 weeks at 65 degrees. then moved it to a secondary for 3 weeks. it read just ove the 5% mark for the OG and the FG was 2.5%

 

[Yuri_Rage]

Well, the potential alcohol scale matches my math: 5% minus 2.5% equals 2.5%. However, something isn't adding up. I bet your OG was higher than 1.040, and an OG of 1.020 seems awfully high, too. Please post as much information as you can about your process and recipe. Without more detailed information, all I can tell you is that you probably don't have a 2.5% beer, but you are at risk for bottle bombs.

 

[Pappers_]

it read just ove the 5% mark for the OG and the FG was 2.5%

My hydrometer shows measurements like a thermometer, with numbers like 1.010 and 1.050, not percentages. Like these photos:

 

[philrose]

yeah. 50% attenuation is not exactly a strong fermentation. Please provide details

 

[Yuri_Rage]

My hydrometer shows measurements like a thermometer, with numbers like 1.010 and 1.050, not percentages.

He's reading the potential alcohol scale (a secondary or even tertiary scale featured on some hydrometers that I'm convinced are specifically designed to confuse n00bs - see "triple scale hydrometer"). It assumes the wort/must will finish at 1.000. It can be a quick shortcut for a vintner to determine potential ABV, since many wines finish near 1.000. Subtracting the finishing potential from the starting potential yields actual ABV.

 

[Hermit]

Well, the potential alcohol scale matches my math: 5% minus 2.5% equals 2.5%. However, something isn't adding up. I bet your OG was higher than 1.040, and an OG of 1.020 seems awfully high, too. Please post as much information as you can about your process and recipe. Without more detailed information, all I can tell you is that you probably don't have a 2.5% beer, but you are at risk for bottle bombs.

The 1.020 curse of extract brewing?

 

[Pappers_]

Thanks Yuri - thank heavens the manufacturer has made this easy for new brewers!

 

[bonzombiekitty]

Also, what at what temp did you take your OG measurements at? Most hydrometers are calibrated for, IIRC, 65 degrees. If you took the measurement and the temperature of the wort was higher, then the hydrometer will give you a lower reading than what it actually is.

 

[malkore]

my guess is the OG is wrong, since its way low for a stout.

the curse of 'not mixing a partial boil with extract thoroughly into the top off water'.

FG does seem a little high though. hopefully these don't become bottle bombs.

 

[remilard]

OG is not low for an Irish Stout.

 

[michaelob]

thanks for the help, must have lunched on my readings. my first 2 brews were great and my readings were good. not sure why my readings are so far off? I tasted it before i bottled and it was good. It has been bottled for 3 days and no bombs. I hope im in the clear, just fd up my reading.

 

[rico567]

I experienced the "curse of 1.020" in my extract days, but only once. It remained a mystery, as the beer (a porter with a higher -about 1.060- OG) turned out to be completely normal. In terms of your bottling time......it may be too early for bombs. I'd wait another week and check the carbonation level.

 

[Brewin06111]

the curse of 'not mixing a partial boil with extract thoroughly into the top off water'.

^^^^ This